In recent years, in response to demands on a miniaturization of electronic devices, an improvement of mounting semiconductor elements on a surface at a high density is required further more. Therefore, in recent years, a so-called stack package type of semiconductor device is employed in which a plurality of semiconductor elements are stacked in multiple stages. In such a stack package type of semiconductor device, since the stacked semiconductor elements are arranged, there may be caused a problem of external noises (electromagnetic interference). Such a noise problem becomes remarkable as the electronic devices are digitalized, increase in speed, and operate in higher frequencies. Then, in order to suppress a noise influence, an electromagnetic wave shielding sheet to shield electromagnetic waves is formed on a sealing material which seals the semiconductor elements (for example, see Patent Literature 1).
As the formation of the electromagnetic wave shielding sheet, for example, there is a known method for manufacturing the semiconductor device disclosed in Patent Literature 2. In the method for manufacturing the semiconductor device disclosed in Patent Literature 2, in a process of sealing the semiconductor element with the sealing material through a transfer molding method using an upper mold and a lower mold, an electromagnetic wave shielding resin is coated on a release film (carrier film) disposed in the upper mold, and the electromagnetic wave shielding resin is transferred to the sealing material and cured thereon when the sealing material is formed.